The present invention relates generally to semiconductor lasers and specifically to a semiconductor laser array emitting a uniform wavefront.
Present state-of-the-art semiconductor laser arrays include one dimensional devices which form a column and are phase locked by evanescent waves. Currently, two-dimensional arrays are being designed which are composed of multiple columns of linear arrays. The scaling of two-dimensional arrays includes the problem of coupling different columns of linear arrays to one another, as a method of phase locking the entire array.
The task of providing a phase locked two-dimensional semiconductor laser array is alleviated, to some extent, by the following U.S. patents, which are incorporated herein by reference:
U.S. Pat. No. 3,996,492 issued to J. McGroddy on Dec. 7, 1976;
U.S. Pat. No. 4,047,124 issued to Comerford et al on Sept. 6, 1977.; and
U.S. Pat. No. 4,163,953 issued to Springthorpe et al on Aug. 7, 1979.
The McGroddy reference discloses an injection laser, having sides chemically etched to provide facing 45 degree mirrors, which can emit lasing light in the same direcion as current going through the p-n junction. This injection laser has a two dimensional array of lasers with the location of each laser being uniformly spaced from an adjacent laser.
The patents of Comerford et al and Springthorpe et al disclose a laser array having reflecting surfaces between adjacent lasers. There remains a need to adapt such laser mirror configurations between two-dimensional laser arrays for producing a unified wavefront. The present invention is intended to satisfy that need.